<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <button id="btn" type="button">点我啊</button>

    <script>
        function onClick() {
            console.log("clicked");
        }
        const btnEl = document.getElementById("btn");
        btnEl.addEventListener("click", onClick, {
            capture: false,
        });
        btnEl.addEventListener("click", onClick, {
            capture: true,
        });
        // 不能直接使用
       console.log(getEventListeners(btnEl));
    </script>

</body>

</html>